Abstract: A capacitive moisture sensor includes a semiconductor substrate, which has a hole. A silicon oxide film is located to close the hole. A pair of electrodes is located on the silicon oxide film. Each electrode is in the shape of a comb, and the electrodes mesh with each other. A silicon nitride film is located on the electrodes to cover and protect the electrodes and on the silicon oxide film between the electrodes. A moisture-sensitive film, the dielectric constant of which varies in response to ambient moisture, is located on the silicon nitride film. The thickness of the substrate is substantially zero under the electrodes to eliminate the parasitic capacitance between each electrode and the substrate.

Abstract: In a method for manufacturing a semiconductor pressure sensor, after a reference pressure chamber is formed inside a semiconductor substrate and a diaphragm is formed from a part of the semiconductor substrate, a heat treatment is performed to form an insulation film, an element, or the like on the semiconductor substrate. At that time, a heat treatment temperature is controlled to be lower than (−430P0+1430)° C. where P0 is an internal pressure (atm) of the reference pressure chamber at a room temperature. Accordingly, crystal defects can be prevented from being produced in the diaphragm.

Abstract: A photo sensor has a first silicon chip and a second silicon chip mounted on the first silicon chip. Photodiodes are formed in an upper surface portion of the second silicon chip to transform light into electric signals, and circuit elements such as a transistor are formed in an upper surface portion of the first silicon chip to form a signal processing circuit, which manipulates the electric signals from the photodiodes. A metallic thin film is provided on the lower surface of the second silicon chip to cover the circuit element as a shielding film.

Abstract: In a thermo pile infrared ray sensor, an opening portion is formed by etching a substrate from a second surface after an n-type poly-Si layer and a thin aluminium layer are formed so that first and second connection portions are formed by parts thereof. An infrared ray absorbent layer is formed on the substrate to cover the first connection portion with a screen print after the opening portion is formed.

Abstract: Magnetoresistive devices are formed on the insulating surface of a substrate made of silicon. The devices are connected in series through an insulating film using a wiring layer formed on the surface of the substrate. An insulating film for passivation is formed to cover the devices and the wiring layer. A magnetic shield layer of Ni—Fe alloy is formed on the passivation insulating film through an organic film for relieving thermal stress to cover one of the devices. After removal of the sensor chip containing the magnetoresistive devices and other components from the wafer, the chip is bonded to a lead frame through an Ag paste layer by heat treatment. Preferably, the magnetic shield layer is made of a Ni—Fe alloy having a Ni content of 69% or less.

Abstract: A sensor has a series circuit, which includes first and second end terminals, a set of thermocouples electrically connected in series between the first end terminal and the second end terminal, and electrical inspection terminals, which extend from corresponding intermediate points in the series circuit between the first end terminal and the second end terminal to divide the set of thermocouples into smaller groups of thermocouples. A resistance value of each group of thermocouples is measured through adjacent two of the first and second end terminals and the electrical inspection terminals while the sensor is in a wafer state. Whether the thermopile infrared sensor is normal is determined based on the measured resistance value of each group of thermocouples.

Abstract: Metal wiring segments, which are located at peripheral positions of a diaphragm, are formed on a main surface of a thick portion of a semiconductor substrate. A ratio S/d is larger than 100, where an area of the diaphragm is S &mgr;m2 and a thickness thereof is d &mgr;m. Further, a total area of the metal wiring segments arranged on first sides of the substrate is larger than total area of the metal wiring segments arranged on second sides of the substrate, where the first sides indicate the sides in parallel with <110> crystalline axis and the second sides indicate the sides in parallel with <100> crystalline axis.

Abstract: An infrared sensor includes a concavity made on a side of a semiconductor substrate and a plurality of sensing areas formed in a thin film area on the back side of the bottom of the concavity. Groups of two thermocouples, three thermocouples and four thermocouples reside in a sensing area in the central part of the thin film area, in another sensing area adjacent the central sensing area and in yet other sensing areas adjacent to the central sensing area, respectively, to compensate for the heterogeneity of heat transfer in the thin film area. Therefore, sensitivity loss is suppressed in the sensing area having a boundary with the substrate. More specifically, the difference in sensitivity between the sensing areas is reduced.

Abstract: In a sensor chip for forming the light receiving elements of a photo-detection sensor, p-type regions of the photodiodes are formed in a surface portion of an n-type epitaxial layer, and they are respectively contacted with electrodes. A deep n+-region is formed in the part of the n-type epitaxial layer between the adjacent p-type regions so as to reach a buried n+-region. Carriers created with the projection of light in the photodiodes are trapped by the deep n+-region (30). An aluminum film serving as a light shielding film is arranged over the part of a silicon substrate between the regions for forming the photodiodes. Thus, the photodiodes can be operated independently from each other.

Abstract: A capacitive moisture sensor is made from an SOI, i.e., silicon-on-insulator, substrate. Two electrodes, between which moisture-sensitive material is interposed, are formed from a thick silicon layer of the SOI substrate by separating the layer with a trench vertically reaching an insulator layer of the SOI substrate. Two substantially vertical sidewalls defining the trench make up a capacitor for moisture sensing. Therefore, by using deep trench, i.e., thick silicon layer, capacitance sensitivity to moisture is readily increased without horizontally widening the electrode or using horizontal surface of the electrode, that is, without enlarging sensor size or complicating fabrication process. In addition, the electrodes are made of silicon, so that corrosion resistivity against moisture is significantly.

Abstract: A capacitance type humidity detecting sensor has two electrodes which face with each other with a gap interposed therebetween to form a capacitance on a silicon substrate having a silicon oxide film on a surface thereof. A humid-sensitive film is formed so as to cover the two electrodes with a silicon nitride film interposed therebetween to protect the electrodes from water passing through the humid-sensitive film. The capacitance between the two electrodes changes in accordance with ambient humidity of the sensor. A switched capacitor circuit formed in a circuit element portion processes a signal which contains change in the capacitance between the two electrodes.

Abstract: A capacitive moisture sensor is made from an SOI, i.e., silicon-on-insulator, substrate. Two electrodes, between which moisture-sensitive material is interposed, are formed from a thick silicon layer of the SOI substrate by separating the layer with a trench vertically reaching an insulator layer of the SOI substrate. Two substantially vertical sidewalls defining the trench make up a capacitor for moisture sensing. Therefore, by using deep trench, i.e., thick silicon layer, capacitance sensitivity to moisture is readily increased without horizontally widening the electrode or using horizontal surface of the electrode, that is, without enlarging sensor size or complicating fabrication process. In addition, the electrodes are made of silicon, so that corrosion resistivity against moisture is significantly.

Abstract: A reference voltage generating circuit is constituted by resistors RE and RF each having a resistance not influenced by an application of pressure. The reference voltage generating circuit is connected between one and the other ends of a bridge circuit. A failure judgement of the bridge circuit is performed based on a comparison of a voltage difference VBC between two midpoints B and C of the bridge circuit and voltage differences VCE and VBE between a reference voltage level of the reference voltage generating circuit and the voltage levels of two midpoints B and C.

Abstract: In the method for manufacturing a semiconductor substrate, a concavity and a connecting hole for connecting the concavity to the outside are formed on a lower face side of a first substrate, and the first substrate is laminated with a second substrate in an atmosphere at atmospheric pressure. A diaphragm is formed by thinning the first substrate from its upper face by polishing. A sealing hole reaching to the connecting hole is formed from the upper face of the first substrate. An oxide film is formed in the sealing hole in a vacuum, whereby the connecting hole is sealed while the pressure of the pressure reference chamber is reduced to a vacuum. In this way, since the pressure reference chamber is pressure-reduced in a final stage, the diaphragm can be prevented from deforming due to pressure difference during polishing.

Abstract: A diaphragm that distorts according to pressure applied thereon and a signal processor circuit are formed on a semiconductor substrate having an (110)-surface-orientation. Stain gauges converting the diaphragm distortion into an electric signal and forming a bridge circuit are formed on the diaphragm. The electric signal from the bridge circuit is processed by the signal processor circuit. A pair of transistors constituting an input circuit of an amplifier in the signal processor circuit are positioned on the substrate to equalize their source-drain current directions. Thermal stress influence on the sensor outputs is minimized since sensor components are formed on the substrate having the (110)-surface orientation, and thereby the pressure applied to the diaphragm is accurately detected.

Abstract: An infrared sensor includes a concavity made on a side of a semiconductor substrate and a plurality of sensing areas formed in a thin film area on the back side of the bottom of the concavity. Groups of two thermocouples, three thermocouples and four thermocouples reside in a sensing area in the central part of the thin film area, in another sensing area adjacent the central sensing area and in yet other sensing areas adjacent to the central sensing area, respectively, to compensate for the heterogeneity of heat transfer in the thin film area. Therefore, sensitivity loss is suppressed in the sensing area having a boundary with the substrate. More specifically, the difference in sensitivity between the sensing areas is reduced.

Abstract: In a thin-film infrared sensor, (100)-oriented semiconductor substrate is used for the sensor fabrication. A surface of the substrate is partially masked to provide an unmasked section where a concave is made and a masked section on the back side of an alley between thin-film sensing areas. An anisotropic etching using an etchant such as KOH is applied to the masked substrate to make the concave (the thin-film sensing areas) and to provide an unetched portion of the substrate at the bottom of the concave on the back side of the alley between the sensing areas. The unetched portion of the substrate makes a rim to support the sensing areas. High concentration Boron doping is not necesarry. Thus, it is possible to reduce deformation of thin-film sensing areas caused by a stress in the rim and to reinforce the rim.

Abstract: In a method for manufacturing a semiconductor pressure sensor, after a reference pressure chamber is formed inside a semiconductor substrate and a diaphragm is formed from a part of the semiconductor substrate, a heat treatment is performed to form an insulation film, an element, or the like on the semiconductor substrate. At that time, a heat treatment temperature is controlled to be lower than (−430P0+1430)° C. where P0 is an internal pressure (atm) of the reference pressure chamber at a room temperature. Accordingly, crystal defects can be prevented from being produced in the diaphragm.

Abstract: In a sensor chip for forming the light receiving elements of a photo-detection sensor, p-type regions of the photodiodes are formed in a surface portion of an n-type epitaxial layer, and they are respectively contacted with electrodes. A deep n+-region is formed in the part of the n-type epitaxial layer between the adjacent p-type regions so as to reach a buried n+-region. Carriers created with the projection of light in the photodiodes are trapped by the deep n+-region (30). An aluminum film serving as a light shielding film is arranged over the part of a silicon substrate between the regions for forming the photodiodes. Thus, the photodiodes can be operated independently from each other.

Abstract: A sensor portion of an integrated photo sensor is composed of a silicon substrate, a photo diode and a signal processing element which are provided on the silicon substrate separately from each other. A shading film is provided on a surface region of the substrate except a region above the photo diode, and an intermediate insulating film made of silicon oxide is provided between the silicon substrate and the shading film. The intermediate insulating film includes a part extending on a light-receiving region of the photo diode, and the part is covered with light transmittable gel having a refractive index approximately equal to that of the intermediate insulating film.